Ladle bottom and ladle

Abstract

A ladle bottom being part of a metallurgical ladle for treating a metal melt as well as a corresponding metallurgical ladle.

The invention claimed is: 
     
       1. Ladle bottom made of a refractory ceramic body with an upper surface, a lower surface and a pouring channel extending between upper surface and lower surface, wherein said pouring channel extends from a diffusor box, being defined by a deepened section of said upper surface, wherein the diffusor box is characterized by the following features:
 a) it is arranged at a horizontal distance to a surface area of the ladle bottom used as an impact area for a metal melt poured onto said ladle bottom, 
 b) it has a vertical step at least along its border facing the impact area, wherein said step has a height of between 40 and 200 mm, 
 c) it has a minimum horizontal area 
 
       
         
           
             
               
                 A 
                 
                   m 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   i 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   n 
                 
               
               = 
               
                 
                   
                     Π 
                     4 
                   
                   ⁢ 
                   
                     
                       ( 
                       
                         0.37 
                         ⁢ 
                         r 
                       
                       ) 
                     
                     2 
                   
                 
                 + 
                 0.3 
               
             
           
         
         and a maximum horizontal area 
       
       
         
           
             
               
                 A 
                 max 
               
               = 
               
                 
                   
                     Π 
                     4 
                   
                   ⁢ 
                   
                     
                       ( 
                       
                         0.08 
                         ⁢ 
                         r 
                       
                       ) 
                     
                     2 
                   
                 
                 + 
                 0.3 
               
             
           
         
         wherein r=radius of the ladle bottom and r≧0.75 m with r max =2 m for all ladle bottoms with an effective radius of ≧2 m, 
         d) an inlet end of said pouring channel is arranged offset the step along its border facing the impact area. 
       
     
     
       2. Ladle bottom according to  claim 1 , wherein the step extends along at least 75% of the border of the diffusor box. 
     
     
       3. Ladle bottom according to  claim 1 , wherein the step extends along the complete border of the diffusor box. 
     
     
       4. Ladle bottom according of  claim 1 , wherein the border defining the outer geometry of the diffusor box has a rectangular, circular or oval shape. 
     
     
       5. Ladle bottom according to  claim 1  wherein the horizontal area of the diffusor box corresponds to 3.7 to 32.9% of the total surface area of the ladle bottom. 
     
     
       6. Ladle bottom according to  claim 5  wherein the horizontal area of the diffusor box is equal or larger than 5.8% of the total surface area of the ladle bottom. 
     
     
       7. Ladle bottom according to  claim 5  wherein the horizontal area of the diffusor box is equal or smaller than 25.5% of the total surface area of the ladle bottom. 
     
     
       8. Ladle bottom according to  claim 1  wherein the pouring channel is arranged at a distance to the step along its border facing the impact area being equal or larger 3 times its maximum horizontal extension. 
     
     
       9. Ladle bottom according to  claim 1  with a distance between a central point along the upper surface of the impact area and a central point along the upper surface of the diffusor box being 30 to 75% of the maximum horizontal extension of the ladle bottom. 
     
     
       10. Ladle bottom according to  claim 1  with a distance between a central point along the upper surface of the impact area and a central point along the upper surface of the diffusor box being 50 to 65% of the maximum horizontal extension of the ladle bottom. 
     
     
       11. Ladle bottom according to  claim 1  with a distance between a central longitudinal axis of a gas purging plug arranged in the ladle bottom and a central point along the upper surface of the diffusor box being 30 to 75% of the maximum horizontal extension of the ladle bottom. 
     
     
       12. Ladle bottom according to  claim 1  with a distance between a central longitudinal axis of a gas purging plug arranged in the ladle bottom and a central point along the upper surface of the diffusor box being 50 to 65% of the maximum horizontal extension of the ladle bottom. 
     
     
       13. Ladle bottom according to  claim 1  with a dam like protrusion between impact area and diffusor box, extending substantially perpendicular to a direction along which a corresponding metal melt will flow from the impact area into the diffusor box after hitting the impact area.